The hopper does not pull out a specific stackable item from a chest when the hopper is completely full except for one partially filled slot. The stackable item in the partially filled slot of the hopper is in the chest where the items are being drawn from but is not the first item in the chest (there is another item closer to the top left of the chest).

What I expected to happen was that the item would get pulled out of the chest regardless of the order.

What actually happened was no items were pulled out of the chest.

Steps to reproduce:
1. Place a hopper and fill 4 of the slots in it with a stack of 64 of any item
2. Place at least one stackable item into the forth slot (do not put a full stack)
3. Place a chest above the hopper and put any item in the chest first (top left slot)
4. Place the stackable item that partially fills a slot in the hopper in the chest anywhere but the first slot
5. Notice that the item is not drawn out of the chest even though there is space for it in the hopper
6. if the placement of the items in the chest are swapped, the hopper works as expected

The inventory of the hopper and the chest can look like the pictures below.